250 is not a lot of dough so you need to shop a bunch. Grab your axe and head to every music store and pawn shop in town. If you rely on floor effects to get your distortions, check out the solid state gear. If buying used, be sure the speaker is good (no cone buzz/rattle when set clean) and the pots (controls) are not scratchy/static/dirty. Try to get 50 watts with a single 12" speaker. This would take you from practice to a gig.

Peavey Bandits are a tough amp for the money.